Have you ever heard of Kaprekar’s constant? Known as 6174, it’s a mysterious number that pops up when you play a simple game with four-digit numbers.
Here’s how it works:
Take any four-digit whole number (no fractions, please). Rearrange the digits in order from highest to lowest, then subtract the smallest arrangement from the largest.
For example:
7641 – 1467 = 6174.
Now try another one. Let’s start with 4615:
6541 – 1456 = 5085
8550 – 0558 = 7992
9972 – 2799 = 7173
7731 – 1377 = 6354
6543 – 3456 = 3087
8730 – 0378 = 8352
8532 – 2358 = 6174
Magically, no matter which number you start with, within seven steps you end up at 6174! (Of course, it doesn’t work with numbers made of the same digits like 0000 or 1111.)
I’ll admit, I discovered something else while trying this – I might be a little dyslexic!
I kept turning numbers the wrong way and spent an hour trying to get it right before finally asking my daughter.
Naturally, she nailed it on the first go.
But isn’t it amazing what our brains can do? Sometimes it feels like we operate in “holiday mode”, never really pushing our minds to their full potential.
Yet, when you see mathematical quirks like this, you can’t help but marvel at the human brain.
I’ve been watching a few YouTube videos lately, and it’s incredible what you can learn, no matter your age. One video showed how to use your fingers like a calculator – a bit like an abacus.
Each finger has a value, and using simple combinations, you can solve sums without ever picking up a pen.
Sounds like a trick, but it really works!
Think about it: how does the brain coordinate our fingers when we play the piano, or let musicians play several instruments with ease? How do we read, understand, and imagine ourselves inside a story just from lines on a page?
Our brains are astonishing. Sure, we may forget a few things as we get older, but when you consider how much our minds can still create – ideas, solutions, and even small innovations – there’s plenty of power left upstairs.
We’ve all had those “aha!” moments where we see something new and wonder, why didn’t anyone think of that before? Maybe this column will inspire you to look at things a little differently – to explore, to question, to learn something new.
So why not give your brain a workout? Try Kaprekar’s constant, or look up how to use your fingers as a calculator – and amaze your friends!

